Diet men and women, these are common things, but the truth is not simple. For example, for gender, we don't
Only don't know their origin, we don't fully understand the necessity of sexual reproduction, in fact, the current earth
There are still many amorphous biodiversity.
Sexual biology research is a very interesting field. Low organisms have gender, such as bacteria that belong to prokaryotic organisms. Different organisms determine that gender have different methods, from molecular basis to biological behavior, and it is not fixed. Some of the gender of the organism is different because of the temperature or humidity, some of the male affiliates, some organisms are mainly responsible for children, and the gender and their related mechanisms and behaviors are only one of the thousands of biological states.
Deciding the nature of men and its weird characteristics
Here mainly introduces the principles of men. In the human world, a variety of cultures and society have a long-term history of "men" with special name and explanation. However, the understanding of the biological essence of "men" is less than 50 years. Although the time for the gender of other organisms is longer, the key Y chromosome for human men's decisions is to discover in 1959; in 2003, scientists tested the DNA sequence of human Y chromosome. Gene research on men not only is interesting, but also a story of scientists who dare to admit mistakes in the research process, and continue to study the story, showing the "men" behavior that is in line with the general traditional definition.
Each normal person is almost all genetic information exists in 46 chromosomes of the nucleus (there are small amounts inside the mitochondria). These 44 have no gender difference, called the common-stained body, and the remaining two are sexual chromosomes with gender difference: one is x, one is Y. Female has two X (remembered xx), and men have X, one y (xy). During the evolution, X and Y are neutralized, initially X and Y, and after YI, it can determine male, and will be obtained from X later. Therefore, it is necessary to say that it is also a male origin that is still in women (rather than the so-called female from the Bible), but the gender system used by human use is not first originated in humans, but billions. Before the year (when there is no one, it originated from low animals.
The Y chromosome of the human (and mammal) also has other weird characteristics. Comparing Y and other chromosomes, it seems to be a dominant chromosome that always "out of the world": As long as there is it, no matter if there is x, it is male. In contrast, if there is any X can't completely determine gender, but also to see if Y, like X to see Y's face. Y chromosomes are selfish, and its main purpose is to make yourself, and don't take care of other chromosomes. The existence of Y is only important to Y yourself, while other chromosomes have active contribution to the collective. All other chromosides, including X, exist in men and women, mother's X chromosome can pass to their son, but only Y chromosome pull gang: only in men, only from father to my son .
Y is the only chromosome that does not have to survive individuals. If there is no X, or no other pair of common-stained chromosomes, people can't be born, and they will die during the embryonic period. Without Y chromosomes, there is no relationship to individual survival, such as women, but still can live longer. Other chromosomes are generally relying on each other, but they do not rely on Y chromosome.
The Y chromosome is the most unlimited chromosome. All other chromosomes have genetic substances (recombinant): Demonstrative 44 is equipped with 22 pairs, and there is DNA recombination between each pair. X chromosomes can also be reorganized in women. Only Y chromosome is special, it is only in XY, but it cannot be unable to group in vast majority. There is a recombination to eliminate evolution after a bad mutation appearing on the chromosome, thereby maintaining the "vitality" of the chromosome. However, in the evolutionary process, the Y chromosome resembles the important area and the X-chromosome reorganization in order to maintain its unique function, so that the Y chromosome cannot be effectively corrected, and the defect is constantly changing, and now human Y In addition to the end of the end, the chromosome can be recombined with the x chromosome in addition to the end of the X-chromosome recombination. As a result, modern human Y chromosome is much smaller than X chromosome.
The Y chromosome relies on other chromosomes, which neither has the same size of recombinant, and does not care about other chromosomes. In a certain sense, it can be said that Y chromosome is like a parasitic. Find gene nature of men's Chinese
In 1959, biologist found Y chromosome decisive male characteristics, people wanted to know what specific regions above Y chromosomes, and a particular gene is the key to determining men. By 1975, Wachtel et al. Proposed a gene H-Y and male decision on Y chromosome. This hypothesis is about 10 years, and by McLaren by McLaren in 1984.
In the 1980s, the laboratory led by Pagek, the MIT, and the modern molecular genetics method finds a gene of determining men. In 1986 they found that a particular small section of Y chromosome contained a gene that determines men. In 1987 they believed that a particular gene ZFY in this section was a gene that determines the male. The key step in this conclusion is determined by the situation of a patient. This patient is characterized by a woman, but the chromosome looks XY (not normal women's XX). The original Y chromosome has an abnormal: Peki, etc. I have discovered that her Y is a small part of the lack, they will include this lack should contain it. Determining the gene's gene, because there is a lack of such genes, even if there is any other portion of the chromosome, male characteristics cannot be produced. Peki et al. Found ZFY gene in the normal male Y chromosome corresponding to this missing section. After this result, it caused great excitement. In the next few years, they did multiple experiments with others and other mammics or even birds. As a result, although they could not prove, and ZFY is to determine the conclusion of mammalian male genes. There are many scientific conferences with many schools and small and small, please please speak, introduce their work.
In a lively, Australia's Sinclair Lab has been a different discovery in 1988: The ZFY gene of the kangaroo is not in the y chromosome, and is not in the sex chromosome, but is in a common color. This result can be because ZFY is not a key gene of a male, that is, Pieji proposed that many of the results support (but there is no prove) at the time is wrong. However, this result may also be because the kangaroo does not use ZFY to determine gender, known to the animal gender determination mechanism is invented invented in the evolutionary process, each mechanism can be different, such as the y chromosome of the fruit, no determination of male genes .
Is Zfy not a breastfeeding gene? In 1990, two Lovell-Badge, Australian Female Scientists and the British Lovell-Badge found another gene SRY. This gene finally has multiple evidence that it is to determine the genes of men, such as: If the human SRY gene of XY is a key base mutin, it will become a woman. If the SRY gene should be introduced, it should be a female mouse, which can make her Male.
So, what is the ZFY of Peki? It turned out that patients with their data were particularly special. Her Y chromosomes were not only defects in the area seen in Peki, but also had defects in another area, and the latter area contained SRY, her SRY defect is a woman The reason, and the ZFY found in 1987 was in the other defect area, and ZFY although the defect, this is not the reason why she is. Such a serious patient is relatively small, analyze a region, let the study have leaving the detour.
Men after the frustration
A conclusion that is attached to the scientific community and general society has proven to be wrong. For scientists, it is generally not very good. Many years later, Peki has quite cool down from the "popular" people invited by the academic circles.
However, Peji did not exit the frontier of the active scientific research. First, Peiki Laboratory did not persist in errors in 1990, but the reason why they reported (two defects first pocked a mistake). Thereafter, the other research, especially the genomic studies of Y chromosomes. Since 1992, they published the small paragraph of human Y chromosome, published all the maps in 2001. On June 19, 2003, the collaborators of the Peiki Lab and the University Sequencing Center of Washington were published and analyzed in Y chromosome DNA sequences. Many interesting and important discovery. Chromosomal sequencing articles often have no fun, and Y chromosome determination results may be the most interesting results in human genome sequencing so far. It can also be said that the publishing of these articles will come out from scientists such as Peki from more than a more than ten years ago.
95% of Y chromosome is a male-specific area, inside and male genes, with a total of 156 transcripts, 78 gene encoding proteins, and finally 27 completely different proteins. About 10% of the genes were moved from X chromosome to Y chromosomes in recent million years, and 20% were earlier from X chromosome, and the rest were some panelad structures. Like Chinese poetry, the DNA's repayment is also the same as the same sequence. Peki et al. Found Y chromosome's male-specific regions repeatedly rewn structure, which is that scientists did not expect. Technically, repetitive structures bring a lot of difficulties to sequencing. In science, these repeated copy structures have a great help to understand Y chromosome.
We mentioned that Y chromosome is blamed, not with other chromosome to exchange genetic substances. Do not reorganize the lack of vitality of genetic substances, constantly accumulating the bad mutations, and cannot effectively achieve good changes. This is one of the main reasons for Y chromosome constantly destroying. The study of the Pek Laboratory found that the Y chromosome repeatedly had a sequence of a series of replicate structures, and these repeated replications have DNA recombination capabilities (specifically called "gene conversion"), Y chromosomes, one and other sections Recombination, which is enabled by self-recombination. This is the first time I know that Y chromosome has a recombination of its male-specific regions. The previous DNA is called non-recombinant region, and now it is called a male specific area. This self-restructuring ability is an important mechanism of Y to self-help during evolution. The large-scale gene conversion appears in every generation of boys, is new discovery, and conjecture that there is often a gene conversion in the common-dyed body and X chromosome, which may also increase "vitality" to other chromosomes.
Y chromosome fate:
Perhaps Y chromosome is metaphor as the least understandable teenager. Compared with all other chromosomes in humans, Y is the most young, which will also be the first dying chromosome, that is, Y is the shortest life chromosome.
In evolution, there is a low level of animals to a certain extent, there is no such y chromosome such as the fly, although there is Y chromosome, it doesn't matter, and it is not the reason for the gender of the Dhafly. Drosophila is determined by comparing the ratio of X chromosomes and common stactions. The Y chromosome used by human beings is about 300 million years to three hundreds of millions of years ago and the X chromosome is different. It was after the birds appeared in the bird. About 1 million to 130 million years ago, the SRY gene used for brain development was stolen by Y chromosome and began to determine men. Since the selfish behavior of Y chromosome, in order to maintain and consolidate the male specific gene, constantly suppressing this region and other chromosome, resulting in decline in the entire recombination ability, and the DNA that cannot be effectively corrected after the decline, so that DNA is constantly deteriorating and shortened And in the world, Y and X of the world are less than one to three disadvantages, and the range of activities can be small. Several reasons, the result is that Y chromosomes are stubborn in order for men, other genes and sequences continue to decrease, and now Y and its "companion" X chromosome is very far more than the size is very far: people X There are about 1,500 genes, but there are dozens of genes above. There is a gene SRY that is lost to a day Y dye. In some rat animals, in fact, the SRY gene is no longer. According to the behavior of my company, it is expected that the entire Y chromosome may also die. 2002 Australian female scientist Marshall GRAVES Equivalence: Human Y chromosome is not tens of millions of years.
Peki et al. Found y, Y chromosomal extortion was definitely more than the previous expected slow, and there was a US male scientist Hawley hurriedly said: Y chromosome died is a great exaggerated rumor. However, if you have any questions: Y's self-reorganization efficiency will be high enough to change it in the end of the death?
Comprehensively, it can be metaphor: Y dyeness is very powerful, you have to decide gender separately because it actually "psychology" is uneasy, afraid of destroying. The y chromosome is unsatisfactory, not with X, which is the reason why it is in our own selfish behavior. Y has to use self-reorganization to try to save his own destiny. However, if there is no SRY or Y chromosome to die, will human beings from harassment of men? If someone is hugging, you can disappointed. It is expected that even if SRY has not, there will be other genes to determine men, and now the y chromosome does not have other chromosomes or mechanisms to determine men. Therefore, if human beings can spend the disaster brought by Y chromosome, it will have a great change, which has changed, which means that "people", and people now, is not the same.
In the end, this paper has been used in the traditional definition of the words of the men and women, and the understanding of modern men and women equality is needed. It is said that Pekie is ambiguity, and it is a man's behavior, not hints that the woman does not have such a behavior, but the author does not create a new vocabulary and lazy borrowing traditional vocabulary. Finally, a joke about comparative animal genome said that if the DNA sequence is compared, then the difference between men and women may be greater than the difference between men and men, but the quantity difference, maybe there is no quality difference: nothing is bad, and Where is the difference. I don't believe this manager can get along with the anomoragua for a certain time. If it is easier to get along with the woman, what article, attracting people's verbal reference rates may not be low.
